Apparatus for determining the specific gravity of gases and vapors



Nov. 28, 1933. HA, ROMP 1,937,437

APPARATUS FOR DETERMINING THE SPECIFIC GRAVITY OF GASES AND VAPORS Filed Aug. 27, 1928 2 Sheets-Sheet l hove/afar:

Nov. 28, 1933. H. A. ROMP 1,937,437

APPARATUS FOR DETERMINING THE SPECIFIC'GRAVITY OF GASES AND VAPORS Filed Aug. 27, 1928 2 Sheets-Sheet 2 ln yen for:

fiend/7X14. Ham/a flan 74m Patented Nov. 28, 1933 v v g APPARATUS For; DETERMINING THE ,S-PE- cine GRAVITYJOF GASES AND VAPORS' Hendrik Arnold Romp, SoebanDjeri i, Sumatra,

' Dutch East indies Application August 27, .1928; Serial No. 302,423, v

. and in the Netherlands March;:14, 19 28 1 i 4 Claims- .(Cl. 2(35-44) This invention relates to apparatus for deter gas. Therefore, the 'specific g ravity' of the gas mining thespecific gravity of gases and vapors, investigated "may be determined by measuring and'which includes among its objects that of the oscillation period and comparison withf-the. providing an oscillatory densimeter for asceroscillation period obtained with a gas of known gtaining the specific" gravity of the gas under in specific'gravity. r vestigation through the oscillations of the densi As compared with hithertoknown and used apmeter. J I paratus' that of the invention is of advantage It is usual to determine the weight of a quanin that, with suitable construction 'and selection tity of gas (this also including a vapor in the of the ma'terial of the apparatus used, it is 'posmipresent specification and claims) which cannot sible to measure the'desired specific gravity in 5' v be directly weighed, from the value of other ma'gvery simple manner. It is calculated from the nitudes which can be directly measured, and-paroscillation period of the system with or in the ticularly from the specific gravity. I r gas to be investigated compared with the oscil- In carrying out such calculations, particularly lation period of the system-with or in a gas'of' 15,,with gases under high pressure, the difliculty-is known specific gravity. The movement 3 of *the 7 that the specific gravity of the gases is not'known system may'be'ma'intained by means of a spring under the conditions of weighing nor can it be with gear mechanism and escapement, by a pen; measured in simple manner with present apparadulum, by means of an electrical apparatusfor tus.- This unknown specific gravity is thus deg by any other means usual in clockworks;

,go; duced from a known specific gravity under dif lhe oscillation periods maybe previously 7 ferent temperature and pressure conditions, and measured in air at atmospheric pressure andsince this deduction can be m'ade'onl y by the use predetermined temperature in order to calibrate of equations of state (Boyle-'G'ay Lussac-;- v. d. the apparatua and in other gases under. co'nd'i Waals)",itis obvious that it is possible only to tions whereby the specific gravity is known, sogaobtain avalue which in general deviatesthe more that it'is possible to determine the constants of from the correct value the, closer the gases are the apparatus by means of which, in gases of un.-' to their critical point (the more the character of known specific gravity also, it is possible to dethe gases difiers from those of an ideal gas). termine' the specific gravityof'said gases from' According tothe present invention these diiii the periods of oscillation. The apparatus "can 3o .culties' are overcome bymeasuring the specific be controlled as desired by repeating the oscil1a--- gravity of the gas under the same or'approx tion-periodmeasurements in air at atmospheric imately the samee'onditions asthe other auxilpressure. j iary magnitudes which are necessary for calcu- Figure l-is aperspective view'oflan oscillatory lating the specific gravity. q r drumwherein use is, made exclusively of l the The'principle of the apparatus according to the mass of a definite volume of gas for influencingf j invention consists in that the gas, the specific the'oscillationperiod of the drum, gravity of'which is to be determined, is placed 'in- Figure "2 is *ajperspective view ofmeans by contact with a periodically moving mechanical which the apparatus shown in- Figure 1; can be. apparatus, the-periods of'which are influenced intercalated into'ja high pressure 'gas line, V v

40 by the specific-gravityof the "gas; the measuring Fig'u'r'et is a view in elevation, pa'rtlyl'in secof the specific gravity is furnished-by'measuring tion, of a 'specialifzedpendulum in which use is" the periods of oscillation. made exclusively of the weight-of ajdefinitevol This principle is utilized advantageously in ume ofthe gas-,f 7

practical manner in two ways hereinafter de- Figure-14 is al-view in elevation, partly in' -se'c scribed, 'as wellasin' the combination thereof. tion, showing. aiorm'of pendulurn whereinnsej ,00

In one method of use the gas forms a constituent is made of "thetwo combined effects.

of the moving element "of a mechanical oscil- Referring now 'in'detail' to the severalfigures latory'system, in the second-the gas serves as a and'firstadverting to that'form-of the invent-ion medium'wh'ereina mechanical system oscillates. shown in Figure 1, an annular-drum 5: is-pro-j Accordingly, use-ismadeeither oi ther'nass or the vide'd which is mounted on a shaft 6 A spring: 7 1 5.

weight of a definite volume of gas in order to places' the drum in position to describe" repeated vary or influence the forces causing an oscillatoscillations in the same manner as does the bal ingmovementot the mechanical system. In both 'anc'eof a-cl'ock; A pin-8 on the shaft S- engages; casesthe oscillation period of the system is, in an-escapement lever which governs theescape general, a function ofthe specific gravity of'the ment wheelflll, thelattenbeingby a m lg cording devices.

P ose a cover 23 having alever construction 24 which spring 13 and which also may operate recording apparatus as in other well known clock or re- Mounted in the drum is a plurality of radial intermediate walls llvwhich form compartments communicating with-the atmosphere through holes 12 and 12' in the outer and inner walls. These holes areso' small that while the gas in the compartment 'is renewed by the centrifugal force engendered by the oscillation v.may be made of invar alloy or use may be made of the drum the result of the measure is not appreciably influenced thereby. In case, therefore, the mechanism operates in an atmosphere of'the same gas as that the specific gravity of which is Y to be ascertained, this gas is also found within in-a case 14 (Figure2) which is attached to the pipe 16 by means of a saddle plate 15. Said casing is intercalated in a by-pass 17 the, latter being I provided with regulating valves 18 and 22 at its 25 inlet and outlet ends, as shown, and being pro-v vided with desirable accessory devices su'chgas pressure gauge 19 andfilter 20. If desired, the

pipe 16 can be provided intermediate the ends of the by-pass with an orifice for measuring The casing 14 may be furnished with renders the -instrument which may be housed within the casing readily accessible for inspec tion, reading the record, etc. V j

The housing 14 being clamped around the pipe 16 easily assumes the temperature of the pipe and the gas flowing therein.

' The apparatus shown in Figure 3 consists of a vertical pendulum 30 whose shaft above the,

suspension or pivot point 31 is provided with a sealed hollow sphere 32. The bob 33 of the pendulum issolid and made of a materialphaving a high specific gravity. The pivot point 31 may be provided with knife edges34. resting upon suitable bearings 35. The hollow sphere 32 may besay. it will maintain any angular positionlin.

which it mayberplaced.

'Ifthis pendulum is suspe nded .inthe gas to be investigated the hollow sphere will be acted,

upon upwardly through jthe resultant. of all forces acting upwardly on the instrument and I if thependulumiis thenoscillated, the oscillatory period will be in inverse ratio to the square root of the specific gravity of the gas. ;-The -pen- .dulumwill show-ashorter oscillation period according as-thedensity of the gas is larger, and. vice versa. {If it bedesired to determine only relatively small variations in specific gravity it. is preferable to design or adjust the pendulum 'so that the pendulum is in approximateindifferent equilibrium, aqgas of the least specific ravity coming into consideration; the ratiopetween the periodof oscillation and the specific 'grav-ityis, then somewhat .less simple; g

closed inja suitable housing. It has not been h u t e es y t r peat ny fih se tails:

The pendulum can -also be connectedin known 7 in Figure 3. The manner in which the pendulum shaft or extended pivot point of the'penduluins.

The rearrangement will require the turning over of. the clockwork mechanism; In order to eliminate the influenceof temperature on the operation of the instrument the pendulum shaft of any other known compensating substance or method.

Figure 4 showsan'apparatus in which the gas modifies the oscillation; period of the system in two ways: first because a volume of gas constitutes part of the oscillatingsystem, and its mass 7 follows the oscillating movement; secondly because a force acts on the system, contrary to the force of gravity and depending on the weight of pivot point 37 and carries an open-sphere 38z The lower side of the pendulum; on :the other hand carries a, closed sphere 39. ;The--'instru-;- ment is designed as'to'structure and relative; weights of the various parts so;-that.the device constitutes a pendulumwhen positioned in 'anl evacuated space. The oscillation period measured under these circumstances; may ,beused for comparing with the oscillation period mea'se: ured when the pendulum oscillates within an atmosphere of the gas under investigation; If the apparatus is placed in a-chamber filled with-1 gastheupward pressure on the lower sphere exerts an influence such as to prolong the'period of oscillation. The upward-pressure on' .the up.-; per sphere is for the greater ,partjneutralizedby the weight of the gas having peneblfatedjinto the sphere. .The resultant-ofallupwardlyjexeg erted forces must accordingly prolorigtheperiod; of oscillation. The mass of thegas in the upper-,

most sphere, however, also moves with theipen dulum. The oscillation, period 5 is likewise; pro- 1 dby this mass, 'Qso that-theinfiuences .of-t;

mass and weight reinforce each others action: In order to renew ;gas;.slow1y fin .thej open:

sphere it, is provided with twopppositelyjpesi ig.

tioned openings 4'0;which; ,arearranged. as shown: 1 on Figure 4. A periodical difference in pressure; results from the oscillatQlT ,mqvement by the.-in-;

ertia of the gas within the'spherein such,a way;

that at the ends of the strok with regardto; h u u d e la onepnen ne th r is. a 1 slight overpressureat the other opening a'slighti. underpressure. Hereby a passage of gasthrough the sphereis created V 6-1 If theapparatus isto, be used' .'for ,determ ,ni the specific gravity; ofa gasj fiflw lginapass'agei1 the densimeterg=maybe arranged in 'a bIQ IlGh of? said passage wherein a vervweak gasfiow is per-:- mittedlso that the pressureis,,practically the m asi at-in-" h g It isd rableto 9 re fil e withthe invention.

' While I have in theabQVe .descriptiondefine embodiment of my invention,,it .i's *to. be;un;der-

to ha t e pre i e, d t ils otropst u ion asset.

,front-ofthe inlet of the s n T e h s n ihan b o ru e sqtha what I believeto be a 'preferredandpractical; 5

gases by means of oscillations comprising means forming an external chamber for receiving the gas to be measured and an oscillatory hollow member within said chamber for containing and moving with a body of the gas to be measured, said member being provided with apertures communicating with said external chamber for permitting a slow exchange of the gas from within to without said oscillatory hollow member.

3. Means for measuring the specific gravity of forming an external chamber for receiving the gas to be measured and an oscillatory hollow member within said chamber for containing and moving with a body of the gas to be measured, said member being provided with apertures communicating with'said external chamber for permitting a slow exchange of the gas from within to without a said oscillatory hollow member, and mechanical means for sustaining the oscillations of said member.

4. Apparatus for measuring the specific gravity of gases by means of oscillations comprising a vertical pendulum whose shaft is extended above its pivot point and a hollow member carried by the extended end or" said shaft, said hollow member being of sufliciently large volume that its movemerit will be measurably resisted by the ambient gas, and a bob carried by the lower end of the pendulum.

' HENDRIK A, ROMP. 

